If $\sin heta=\frac{x^2+y^2}{x^2-y^2}$, then

Question

If $\sin 	heta=\frac{x^2+y^2}{x^2-y^2}$, then

Professor PC Thomas Classes · Answer

Since $|\sin	heta| \le 1$, $|x^2+y^2| \le |x^2-y^2|$, which requires $x=0$ or $y=0$ (excluding both to avoid $0/0$).